Eyeglass-lens.



I l sYLvnsrRi sLAeLE,

To lcli/ZZ k'urhfom/"L't may concern."

Be it known that L SYLvEsTRESLAGLE, a

citizen of the United States, residing at State are invariably usedbyp'ersons offorty years of age or more where presbyopia has already iset 1n. They are useless and injurious to eyes Where the power ofaccommodation.still` 15 lower section for close work. Thesel glasses12o. remains, for the reason that the `involuntary action of the ciliarymuscles will ,alter the 'focal ower of the crystalline lens of the eyeand tlie motor-muscles will cause the eyes 'to slightlyy converge `when.an eHort is made to i 25 read or examine work at a short distance. Thisresults ina prisrnatic effect of thelenses,

causes severe strain, and 'in many cases the `line of vision orl thefocal line is not directed j from the macula through the lens of the eye`3o `to the work', but to a pomt either above or be low the work,--resulting in imperfect vision.,

y Thesec tional lenses referred to are invariably made of differentfocal distances, the'uplper lenses being designed for the correctionior`35` permetropia, myopia,4 or astigmatism, `wlnle the lower lenses-havevadiiterent focal len th `or distance forfreading purposes, or, in ot erwords, the eye, owing to presbyopia,remains constant, there being nomovement ofl 'the'f 4o ciliarymuscle, and theline of vision is directedthrough the upperfl'en's of a predetermined ocal -leng-tnto correct the'ametropic condition, or through'the lower lenses ofl shorter focaldistance for reading. f It has alsobeen` roposed to Asupply glasses withshortffocus lenses,` cemented or otherwisese'c'ure'd to. longr focuslenses; but in this .casealso the glasses are designed for use only on:persons Where presbyopia has already set in. 1

y 5o Up tothe/ present `time no` glasses have been made for .use onametropic eyes from the ages of six to forty-fivel years `wherepresbyopia has not! set in and where provision is made forthecorrectionof distant vision vand v 5 5 4to permitfreading or the examination ofwork Specification` f Letters Patent.l Application fue@ piu 26,1905.Sentmenat-'159.

videap or ,STATE ooLIeE,'l PENNSYLVANIA. l l lYEenASs-Lns.'

at a'close range without disturbing the equilibriumof the motor-muscles.

The

present invention is designed to proair. of lenses or spectacles forbinocular vislon, in which distant objects may be viewed, and forreading or the examination of work 'at a close range, the lenses beingof' the same focal distance, as lthe ciliary muscles of the eye actinvoluntarily to alterthe sha e of the crystalline lensinaccordance with.t e focal distance ofthe object beingviewed.v

A further'objectof the'invention is to construct lenses for binocularvisioninWhic-h the kmain lenses are designedv for the correction ofhypermetropia, myopia, or astigmatism, while the lauxiliary lenses arearranged and disposed with a view of neutralizing prisvranged that theirfocal centers arenearer to each Otherthanthe focal centers of thedistance-lenses inforder to accommodate the inthe eyes when exvoluntaryconvergence of arniningan obj ect-at` closerange.

With these and other objects in view, as will more fully hereinafter ation consists 1n certain nove struction and arran features of conementof parts hereinl s @FF-10E;

\ matic effect of the distance lenses While readi nig, sald auxiliarylenses being further soarpear, the invenaftervfully describevillustrated in the `ac- .companying drawings and particularlypointedout 1n the ap pendedclaims it being understood that various changes inthe form, proportions, size, and minor :details ol' the struc- I ture.may be made withoutdeparting from the spirit or sacrificing any of theadvantages. ofthe invention. 7

In the accompanying drawings, Figure l is a `face view of a pair o fspectaclesfor eyeglasses constructed in :accordance with the invention.'Fig 2 is a transverse sectional view of one of the lenses, on the'line2 2 of. Fig. 1. Figs.' 3,"4',and 5' are'viewssimilar to- Fig-2,.illustrating slight modifications of the i invention. `Fig. 6 1s adiagram illustrating the ydifferent o tical centers and uniform focaldistances o Athe lenses.

f Similar characters ployed to.

lngs

vform (shown in Figs. 2'and- 3) for the correction'of hv ermetroia or ofconcave lform (shownln 1gs.'4 an 5) for the correction of myopia, theselenses bein-gof ordinary type Y of vreference `are em- 'i indicatecorresponding arts .throughout the several figures of the rawv "105 Thedlstance-lens 10 may be of the convex ing a convex face the outer faceof the auxiliary lens will also be convex, as shown at 12', or ifattached to a concave lens, as shown in Figs. 4 and 5, the outer face ofthe auxiliary lens will be concave, as shown at 13 inFiCs.

v4 andA 5, while the inner face ofeach of t e auxiliary lenses willcorrespond to the shape of that face of the main lens to which it issecured or with which is in alinementu. Thus in Figs. 2 and 4 theauxiliary lenses are shown as secured, as by cement, .to the outer facesof the inain lenses, and the adjacent faces of theA main and auxiliarylenses are of complementary s'ha e, so that one fits closely to theother; and t e outer-face, of each. auxiliary lens is curved on a convexline or concave line 'main lens forms, in effect, a half-lens.

corres 'ending to the similar curvature of the main ens to which it isattached. In Figs. 3

` and 5'the auxiliary lenses are shown as placed in openin s extendingthrough the main j lenses, an in these cases the rear faces of theauxiliary lenses follow exactly the curvaturesv of the inner faces ofthe main lenses.

It will be observed that'in all of the constructions illustrated theauxiliary lens ta.

pers in thickness from one edge to a diametrically opposite point at theopposite edge, so that that portlon protruding beyond the The auxiliarylensesv l(shown in Figs. 2 and 3) therefore, are vh alf concave-.convexor converging meniscus lenses, with the thicker porthe hypermetropicmain lens and with theV tion toward the 'base or lower edge of the mainlens, while in Figs. 4 and 5 ,the auxiliary lens, or that .portion ofVit which protrudes beyond the outer face of the main lens, is also ahalf-meniscus, with its thicker edge nearest the optical center ofvthecrnain lens, so that with the exce tion of minor changes incurvature of the ens-face the half-meniseus of Fig. 2 for ahypermet opicmain lens may be applied in reverse pvesition to a myopie rnain lens,such as is sho n in Fig. 4, while in the lens shown in Figs. 4 and 5 thesame theory is followed to the extent of placing the thicker edge of theauxiliary lens toward the base of thicker portion of the auxiliary lensof Fig. 5 toward the optical center of a myopie lens.

The optical centers of the main lenses are at a in Fig. 1 but in viewingan obj ect at close range the eyes will naturally converge, so that theoptical centers or axes of the auxiliary lenses must be brought nearerlto each other. In practice it is found best for a normal readingdistance of thirty-three and onethird centimeters to arrange the opticalcenters ofthe auxiliary lenses on lines radiating from the centers a andat an anglev of twenty' degrees inward from the vertical planes oftheThe auxiliary lens llis of a shape corre-.-

optical centers a, while the auxiliary lenses occupy a ositioncorresponding exactly to the line o vision for close work-that is to psay, in`the line a l), extending from the o tical center aof the mainlens and through the optical center of the auxiliary lens. The radialline ar b extends through that diametrical plane of the auxiliary lens'in which its thinnest and thickest edges are dis nosed, the thinnestortion being nearest t e optical center. e or aconverging lens anddistant from such'optical center for a divergin lens.

Both the main and the auxiliarylenses have uniform focal distances. In'using the distance-lenses@ represents the macula ofthe retina inalinement with the center of the crystalline lens, y the focal center ofthe main distance-lens, and at z isf the focal point or focal distanceof the main lens. The arcuate linez zrepresents the focal distance ofboth lenses, and when the eyes are turned down for close reading theywill naturally converge to some extent, and if'the auxiliary lenses wereabsent the prisrnatic effect of the main lenseswould prevent. reading orthe examination of objects at close ran e. 'These auxiliary lenses,however, are so isposed as to prevent prismatic effect, and theirsecondary axes are such that the line of vision will be theoreticallycorrect.

Havin thus described the invention, what is claime is,

1. In` eyeglasses 0r spectacles of the class descr-ibed,.an auxiliarylens carried by each main lens, tne focal distance through that portionof the glasses which includes the auxiliary lens being the same as thefocal distance throu h the main lens.

2. n eyeglasses or spectacles of the class described, an auxiliary lenscarried by each main lens, and of varying thicknessto correct theprismatic effect of the main lens, the focal distance through thatportion of the glasses which includes: the auxiliary lens being the sameas the focal distance through the main lens. A

3. In eyeglasses or spectacles of the class described, an auxiliary lenscarried by each. main lens and varyin in thickness in a diametricalplane exteni the lens to the other, such diametrical plane beingarranged on a line radiating from the ng from one edge of ICO IIO

optical center of the main lens, the focal distance throu h that portionof the glasses which inclu es the auxiliary lens being the Tame as thefocal distance through the main ens.

4'. In eyeglasses or spectacles of the class described, auxiliary lensescarried one by each of the main lenses and having their optical centersor axes nearer to each other than the optical centers or axes of themain lenses, said auxiliary lenses being graduated in thickness indiametrical plane's extending from edge to edge of such auxiliarylenses,the

v ldiaijnetric'al planes bein disposed on lines radiating fromlth'eoptica lenseswand the focal distance throu hzthat portion of the glasseswhich includes t eauxiliary lenses being the same as the focal jdistancethroughthe main lenses. i

5. ln eyeglasses ory spectacles of the class describe an'auxiliaryfle'ns substantially of half-meniscus -forrn secured to theouter face of each niain lensyt'he focal distance throu h n thatportion'of theglasses which includest e A Outer face of each yofthe'half-rneniscus being so arranged `with auxiliary lens bein-g thesaine as the focal disf tance through the niain' lens. i l '6. Ineyeglasses or spectacles of the class described, an auxiliary lensapproximately' of half-ineniscusf Inainlens, the thicker edge centers ofthe main which inclu same as the focal distance through the main ornrand secured to the i prlsniatic effects, the focal disthat es theauxiliary lens being the as to correct tance throu lens.' l V v7. lIneyglasses or spectacles of the class described, distance and reading'lenses of uni-` respect to the optical centerof said inain lens iportion of the. glasses f' form focal distance, the optical centers ofthe

